Prostheses, Tools And Methods For Replacement Of Natural Facet Joints With Artificial Facet Joint Surfaces

Abstract

Cephalad and caudal vertebral facet joint prostheses and methods of use are provided. The cephalad prostheses are adapted and configured to be attached to a lamina portion of a vertebra without blocking a pedicle portion of the cephalad vertebra.

1 - 102 . (canceled)  
     
     
         103 . A facet implant comprising: 
 a superior implant having an articulating surface and a fixation surface and being configured for placement on a superior articular facet;    a inferior implant having an articulating surface and a fixation surface and being configured for placement on an inferior articular facet and for interacting with a translaminar fixation mechanism, whereby the articulating surface of the superior implant and the articulating surface of the inferior implant are configured to interact; and    a translaminar fixation mechanism for securing the inferior implant to the inferior articular facet.    
     
     
         104 . The facet implant of  claim 103  wherein the translaminar fixation mechanism comprises at least one of: a translaminar screw, a bolt and a fixation pin.  
     
     
         105 . The facet implant of  claim 103  wherein at least one of the superior implant and the inferior implant comprises a surface fixation mechanism.  
     
     
         106 . The facet implant of  claim 105  wherein the surface fixation mechanism comprises at least one of: one or more pegs, one or more pips, ridges, one or more screws.  
     
     
         107 . The facet implant of  claim 105  wherein the surface fixation mechanism comprises multiple regions wherein each of the regions has ridges oriented in a different direction.  
     
     
         108 . The facet implant of  claim 103  wherein at least one of the fixation surfaces of the inferior implant and the superior implant has at least one of: a porous coating, a porous onlay material, a biologic coating, and a surface treatment.  
     
     
         109 . The facet implant of  claim 103  wherein the articulating surface of the superior implant is generally curved.  
     
     
         110 . The facet implant of  claim 103  wherein the fixation surface of the superior implant is generally curved.  
     
     
         111 . The facet implant of  claim 103  wherein the articulating surface of the inferior implant is generally curved.  
     
     
         112 . The facet implant of  claim 103  wherein at least one of the articulating surfaces of the inferior implant and the superior implant is composed of at least one of: cobalt, chromium alloy, ceramic, UHMWPE, pyrolytic carbon, and Ti/Al/V.  
     
     
         113 . A facet implant comprising: 
 a superior implant having a fixation surface and a generally curved articulating surface, the superior implant being configured for placement on a specifically prepared articulating surface of a superior articular facet; and    an inferior implant having a fixation surface and a generally convex articulating surface, the inferior implant being configured for placement on a specifically prepared articulating surface of an inferior articular facet, whereby the generally curved articulating surface of the superior implant and the generally convex articulating surface of the inferior implant being configured to interact.    
     
     
         114 . The facet implant of  claim 113  wherein at least one of the superior implant and the inferior implant comprises a surface fixation mechanism.  
     
     
         115 . The facet implant of  claim 114  wherein the surface fixation mechanism comprises at least one of: one or more pegs, one or more pips, ridges, and one or more screws.  
     
     
         116 . The facet implant of  claim 114  wherein the surface fixation mechanism comprises multiple regions wherein each of the regions has ridges oriented in a different direction.  
     
     
         117 . The facet implant of  claim 113  wherein at least one of the fixation surfaces of the inferior implant and the superior implant has at least one of: a porous coating, a porous onlay material, a biologic coating, and a surface treated to facilitate bone ingrowth.  
     
     
         118 . The facet implant of  claim 113  wherein at least one of the articulating surfaces of the inferior implant and the superior implant is composed of at least one of: cobalt, chromium alloy, ceramic, UHMWPE, paralytic carbon, and Ti/Al/V.  
     
     
         119 . A facet implant comprising: 
 a superior implant having a fixation surface and a generally curved articulating surface, the superior implant being configured for placement on a specifically prepared articulating surface of a superior articular facet;    a inferior implant having a fixation surface and a generally convex articulating surface, the inferior implant being configured for placement on a specifically prepared articulating surface of an inferior articular facet and for interacting with a translaminar screw, whereby the articulating surface of the superior implant and the articulating surface of the inferior implant being configured to interact; and    a translaminar fixation mechanism for securing the inferior implant to the inferior articular facet.    
     
     
         120 . A method for providing articulating surfaces for facet joint articular facets comprising: 
 removing a portion of a superior articular facet or an inferior articular facet;    using a surgical instrument to prepare the articulating surface of the inferior articular facet for an inferior implant;    using a surgical instrument to prepare the articulating surface of the superior articular facet for a superior implant;    placing the inferior implant on the inferior articular facet such that an articulating surface of the inferior implant is positioned on the articulating surface of the inferior articular facet;    placing the superior implant on the superior articular facet such that an articulating surface of the superior implant is positioned on the articulating surface of the superior articular facet;    wherein the articulating surface of the superior implant and the articulating surface of the inferior implant are configured to articulate with one another.    
     
     
         121 . The method of  claim 120  wherein each of the steps are repeated on articular facets on a contralateral side of the facet joint.  
     
     
         122 . The method of  claim 120  wherein the articulating surfaces of the superior and inferior articular facets are prepared to accommodate the superior and inferior implants.  
     
     
         123 . The method of  claim 122  wherein the articulating surfaces of the superior and inferior articular facets are prepared such that the shape and dimension of superior articular facet resembles the superior implant and the shape and dimension of the inferior articular facet resembles the inferior implant.  
     
     
         124 . The method of  claim 120  wherein the inferior and superior articulating surfaces are prepared by the same surgical instrument.  
     
     
         125 . The method of  claim 120 , further comprising securing the inferior implant to the inferior articular facet with a translaminar fixation mechanism.  
     
     
         126 . The method of  claim 125  wherein securing the inferior implant to the inferior articular facet with a translaminar fixation mechanism comprises using an aiming device to position the translaminar fixation mechanism.  
     
     
         127 . The method of  claim 125  further comprising drilling a translaminar hole for the translaminar fixation mechanism.